Nanoparticle sampling in academic labs

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Presented at the Division of Chemical Health and Safety technical sessions at the Denver 2011 American Chemical Society Meeting

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Nanoparticle sampling in academic labs

  1. 1. University of North Carolina at Chapel Hill Catherine Brennan NANOPARTICLE AIR MONITORING IN A UNIVERSITY RESEARCH SETTING
  2. 2. <ul><li>Nanotechnology Safety Program </li></ul><ul><li>Nanoparticle Instruments </li></ul><ul><li>Preliminary Data – Nanomedicine Clean Room </li></ul><ul><li>Future Plans – TiO 2 and Carbon nanotubes </li></ul><ul><li>Challenges at Universities </li></ul>Overview
  3. 3. Nanotechnology at UNC Chapel Hill <ul><li>Aerosol Research, Nanomedicine, Materials Science, Environmental Sciences, Use in Research Animals </li></ul><ul><li>Center for Nanotechnology in Drug Delivery – 4 Investigators </li></ul><ul><li>Carolina Center of Cancer Nanotechnology Excellence – 4 Project Leaders, 11 Investigators </li></ul><ul><li>Current “Known” Nano Investigators at the University ~ 34 </li></ul>
  4. 4. Nanotechnology Safety Webpage
  5. 5. Nanomaterial Risk Level (NRL) NRL Type of Nanomaterial Practices Engineering Controls Personal Protective Equipment (PPE) 1 Polymer matrix <ul><li>Standard Laboratory Practices including: </li></ul><ul><li>Lab Safety Plan should be updated with NRL defined </li></ul><ul><li>Labeling of storage containers of nanomaterials with both the chemical contents and the nanostructure form </li></ul>Fume hood or biological safety cabinet (Class II Type A1, A2 vented via a thimble connection, B1 or B2) Standard PPE (lab coat, gloves, safety glasses with side shields) 2 Liquid dispersion <ul><li>NRL-1 practice plus: </li></ul><ul><li>Use secondary containment for containers that store nanomaterials </li></ul><ul><li>Wipe contaminated areas with wet disposable wipes </li></ul><ul><li>Dispose of contaminated cleaning materials as segregated nanomaterial waste </li></ul>Fume hood or biological safety cabinet (Class II Type A1, A2 vented via a thimble connection, B1 or B2) or approved vented enclosure (e.g., Flow Sciences vented balance safety enclosure [VBSE]) <ul><li>NRL-1 practice plus: </li></ul><ul><li>Nitrile gloves </li></ul><ul><li>Safety goggles </li></ul>3 Dry powders or aerosols <ul><li>NRL-2 practice plus: </li></ul><ul><li>Vacuum with HEPA-equipped hand vacuum cleaner </li></ul><ul><li>Label work areas with “Caution Hazardous Nanoscale Materials in Use” </li></ul>Fume hood or biological safety cabinet (Class II Type A1, A2 vented via a thimble connection, B1 or B2) or approved vented enclosure (e.g., Flow Sciences vented balance safety enclosure [VBSE]). HEPA filtered exhaust preferred for fume hoods containing particularly “dusty” operations. NRL-2 practice plus: N95 respirators are required if work operation must be done outside of containment 4 Dry Powders or aerosols of parent materials with known toxicity or hazards <ul><li>NRL-3 practice plus: </li></ul><ul><li>Baseline medical evaluation or employees including physical exam, pulmonary function test (PFT) and routine blood work. </li></ul><ul><li>Access to the facility should be permitted only to persons who are knowledgeable about the hazards of the material and the specific control measures implemented to avoid exposures and/or environmental releases. These control measures should include work practices (SOPs), engineering controls, spill and emergency procedures, personal protective equipment, disposal procedures, and decontamination/clean up procedures. Department procedures should address the designation and posting of the laboratory, how access will be controlled, and any required entry and exit protocols. </li></ul>Fume hood or biological safety cabinet (Class II Type B1 or B2) or glove box or approved vented enclosure (e.g., Flow Sciences vented balance safety enclosure [VBSE]). HEPA filtered exhaust with Bag-In/Bag-Out capability preferred for hoods, BSCs, and gloveboxes. NRL-3 practice plus: Need determined and respirator selected with reference to the engineering controls in use and potential for aerosol generation
  6. 6. Nanotechnology Safety Policy(2010) <ul><li>Principal Investigators </li></ul><ul><ul><li>Designate and address use and disposal as part of individual lab safety plan (CHP) </li></ul></ul><ul><ul><li>Generate SOPs for specific work operations involving nanomaterials </li></ul></ul><ul><ul><li>Ensure lab personnel are trained in hazards and uncertainties associated with nanomaterials </li></ul></ul><ul><li>Laboratory Employees </li></ul><ul><ul><li>Review Lab Safety Manual chapter on nanotechnology and Nanomaterial Risk Level table </li></ul></ul><ul><ul><li>Take Nanotechnology Safety online training </li></ul></ul><ul><ul><li>Review and follow SOPs for specific work operations </li></ul></ul>
  7. 7. Nanotechnology Safety Policy <ul><li>EHS </li></ul><ul><ul><li>Review and provide feedback on lab safety plans </li></ul></ul><ul><ul><li>Provide hazard assessments upon request </li></ul></ul><ul><ul><li>Continuously update nanotechnology safety resources (Lab Safety Manual, Nanomaterial Risk Level table, Nanotechnology Safety training) </li></ul></ul><ul><ul><li>Annually review and update the policy as new findings and regulations are announced </li></ul></ul>
  8. 8. NIOSH Guidance Document <ul><li>Approaches to Safe Nanotechnology: Managing the Health and Safety Concerns Associated with Engineered Nanomaterials (2009) </li></ul><ul><li>Suggested Air Sampling Strategy – Nanoparticle Emission Assessment Technique (NEAT) </li></ul><ul><ul><li>Use of direct read instruments (CPC and OPC) to determine particle number concentration at potential emission sources compared to background </li></ul></ul><ul><ul><li>If elevated, collect filter based, source specific air samples </li></ul></ul><ul><ul><ul><li>One analyzed by Transmission Electron Microscope (TEM) or Scanning Electron Microscope (SEM) for particle identification and characterization </li></ul></ul></ul><ul><ul><ul><li>One analyzed for elemental mass concentration </li></ul></ul></ul>
  9. 9. UNC Direct Read Instruments <ul><li>Condensation Particle Counter (CPC) </li></ul><ul><ul><li>TSI 3007 </li></ul></ul><ul><ul><ul><li>Hand-held (3.8 lbs) </li></ul></ul></ul><ul><ul><ul><li>Uses IPA to condense on particles so they can be counted </li></ul></ul></ul><ul><ul><ul><li>Measures total number of particles per cubic centimeter (#/cm 3 ) independent of chemical identity and size </li></ul></ul></ul><ul><ul><ul><li>Particle size range between 10-1000 nm </li></ul></ul></ul><ul><ul><ul><li>Range of detection 0-100,000 #/cm 3 </li></ul></ul></ul><ul><ul><ul><li>Is material (regardless of size) being released? </li></ul></ul></ul><ul><ul><ul><ul><li>Determine sources </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Determine appropriate controls </li></ul></ul></ul></ul>
  10. 10. UNC Direct Read Instruments <ul><li>Optical Particle Counter (OPC) </li></ul><ul><ul><li>MetOne HHPC-6 </li></ul></ul><ul><ul><ul><li>Hand-held (2.2 lbs) </li></ul></ul></ul><ul><ul><ul><li>Optical counting using laser light scattering </li></ul></ul></ul><ul><ul><ul><li>Measures total number of particles per liter (P/L) independent of chemical identity </li></ul></ul></ul><ul><ul><ul><li>Over 6 size ranges (300nm, 500nm, 700nm, 1000nm, 2000nm, 5000nm) </li></ul></ul></ul><ul><ul><ul><li>Range of detection 0 to 70,000 P/L </li></ul></ul></ul><ul><ul><ul><li>Can determine size range of particles based on concentration </li></ul></ul></ul><ul><ul><ul><li>Used in conjunction with CPC </li></ul></ul></ul>
  11. 11. UNC Direct Read Instruments <ul><li>Nanoparticle Surface Area Aerosol Monitor </li></ul><ul><ul><li>TSI AeroTrak 9000 </li></ul></ul><ul><ul><ul><li>Portable (15.8 lbs) </li></ul></ul></ul><ul><ul><ul><li>Diffusion charger plus electrometer </li></ul></ul></ul><ul><ul><ul><li>Indicates surface area of particles deposited in lung (Tracheobronchial and Alveolar regions) </li></ul></ul></ul><ul><ul><ul><li>Particle size range between 10-1000 nm </li></ul></ul></ul><ul><ul><ul><li>Concentration range </li></ul></ul></ul><ul><ul><ul><ul><li>TB = 1 to 2500  m 2 /cc </li></ul></ul></ul></ul><ul><ul><ul><ul><li>A = 1 to10,000  m 2 /cc </li></ul></ul></ul></ul>
  12. 12. Nanomedicine Clean Room <ul><li>Multi-user space (Class 10,000) </li></ul><ul><li>Incorporation of anti-neoplastic agents into particles </li></ul>BSL 2 hood Walk in hood Bench Chemical Hood refrige. cabinet freezer cabinet Controlled humidity room On top of shelf refrige. Bead Harvester
  13. 13. Clean Room – CPC Data <ul><li>Background measurements during group meeting </li></ul><ul><li>Placed in center of room on shelf above bench top </li></ul><ul><li>Every 60 seconds over 1.47 hr time period </li></ul>Mean (#/cm³) 14.5 Min. (#/cm³) 11.0 Max. (#/cm³) 28.0 Std. Dev. (#/cm³) 2.29 Sample Time (secs) 6420 Time (secs) #/cm 3
  14. 14. Clean Room – OPC Data Time (hr:min:secs) Particles/Liter Background (03/22/11 )
  15. 15. Clean Room – CPC Data <ul><li>Follow-up measurements during active lab work </li></ul><ul><li>Did see minor spikes but mostly tracks with mean </li></ul>Background 03/24/11 03/29/11 Date Start/End Time Range (#/cm 3 ) Mean (#/cm 3 ) Averaging Interval (seconds) Sample Length (hr:min) 3/22/11 1:46pm/3:33pm 11-28 14.5 60 1:47 3/24/11 8:35am/12:29pm 4-35 10.2 60 3:54 3/29/11 8:37am/2:34pm 6-97 17.0 60 5:57
  16. 16. Clean Room - OPC <ul><li>Can not compare OPC and CPC side to side </li></ul><ul><li>Spikes do sometimes track with time </li></ul>03/24/11 (OPC Data) 03/24/11 (CPC Data)
  17. 17. Clean Room <ul><li>Moved next to bead harvester </li></ul><ul><li>Instruments placed on top of fridge </li></ul>BSL 2 hood Walk in hood Bench Chemical Hood refrige. cabinet freezer cabinet Controlled humidity room refrige. Bead Harvester
  18. 18. Clean Room – CPC Data (3/31) <ul><li>Saw highest numbers and definite spikes </li></ul><ul><li>Harvester process captures nanoparticles in solution </li></ul>03/31/11 Date Start/End Time Range (#/cm 3 ) Mean (#/cm 3 ) Averaging Interval (seconds) Sample Length (hr:min) 3/22/11 1:46pm/3:33pm 11-28 14.5 60 1:47 3/31/11 8:47am/1:58pm 2-9300 492.6 60 5:11
  19. 19. Clean Room – OPC (3/31) <ul><li>OPC data off due to vibration? </li></ul><ul><li>Both instruments affected by movement, opening closing doors, equipment cycling </li></ul><ul><li>No further data - lab contact left university </li></ul>03/31/11 (CPC Data)
  20. 20. Future - Aerosolization Research <ul><li>Nebulizing nanomedicine particles into mice </li></ul><ul><li>Occurs in ductless hood in common animal procedure room </li></ul><ul><li>Project currently on hold </li></ul>
  21. 21. Titanium Dioxide <ul><li>New guidelines released from NIOSH </li></ul><ul><li>CURRENT INTELLIGENCE BULLETIN 63 - Occupational Exposure to Titanium Dioxide (2011) </li></ul><ul><li>Delineates differences between fine and ultrafine (<100 nm) TiO 2 and sets different OELs </li></ul><ul><li>Outlines new exposure limit for ultrafine TiO 2 = 0.3 mg/m 3 as 10-hr TWA </li></ul><ul><li>Also lists ultrafine TiO 2 as a potential occupational carcinogen </li></ul>
  22. 22. Future TiO 2 Monitoring Plans <ul><li>UNC Physics lab synthesizing TiO 2 nanotubes (5 nm diameter, 50 nm length) </li></ul><ul><li>Concerns about weighing out dry nanotube powder on bench-top </li></ul><ul><li>Happened to be moving to a new lab space </li></ul><ul><li>Background measurements taken before occupying </li></ul><ul><li>Will follow up once research begins </li></ul>
  23. 23. Future TiO 2 Monitoring Plans <ul><li>UNC Environmental Sciences fog chamber used to study nanoparticle aerosols (NiO, TiO 2 ) </li></ul><ul><li>Need to periodically clean chamber (Particles attach to poly and in between cracks) </li></ul><ul><li>Recommended PPE for cleaning but will also do monitoring </li></ul>
  24. 24. Carbon Nanotubes <ul><li>NIOSH draft Current Intelligence Bulletin: Occupational Exposure to Carbon Nanotubes and Nanofibers </li></ul><ul><li>Proposed REL of 7  g/m 3 as 8-hr TWA </li></ul><ul><li>Several UNC physics lab working on synthesis of carbon nanotubes </li></ul><ul><li>Manipulate in dry form outside engineering controls </li></ul><ul><li>Future plans to perform monitoring </li></ul>
  25. 25. Challenges at a University <ul><li>Vast variety of nanomaterial research projects </li></ul><ul><li>Day to day processes change, timing not consistent as in industrial setting </li></ul><ul><li>Multiple users in same space working on different independent projects </li></ul><ul><li>Type of nanoparticles (chemical composition, size, surface area, shape, etc.) being worked on changes constantly </li></ul><ul><li>Users/Contacts change frequently </li></ul>
  26. 26. Challenges at a University - EHS <ul><li>Each hazard assessment is an independent research project (lack of time for EHS Professional) </li></ul><ul><li>Must keep up to date on current literature and regulations </li></ul><ul><li>Start working on specific assessment and abruptly ends due to someone leaving or change in research </li></ul><ul><li>Handheld or portable instruments are expensive </li></ul><ul><ul><li>OPC ~ $4000 </li></ul></ul><ul><ul><li>CPC ~ $9000 </li></ul></ul><ul><ul><li>Surface Area ~ $10,000 </li></ul></ul>
  27. 27. The Good News <ul><li>Education on unknown hazards of nanomaterials is working and researchers are requesting hazard assessments </li></ul><ul><li>Technical nano conferences are integrating EHS concerns and researchers are coming back asking questions </li></ul><ul><li>Researchers are interested in how their nanoparticles are behaving (clean room) </li></ul><ul><li>Spirit of collaboration especially in early stages of nanomaterial risk assessment </li></ul>
  28. 28. What University’s Need <ul><li>EHS nanotechnology specialists to perform monitoring </li></ul><ul><li>Guidance from NIOSH on monitoring protocols (training course?) </li></ul><ul><li>Collaboration with Environmental Sciences/Aerosol Researchers to work together on “projects” and publish results </li></ul><ul><li>EHS professionals sharing their experiences </li></ul>
  29. 29. <ul><li>Catherine Brennan </li></ul><ul><li>Chemical Hygiene Officer </li></ul><ul><li>Environment, Health & Safety </li></ul><ul><li>[email_address] </li></ul><ul><li>919-843-5331 </li></ul>Contact Information:
  30. 30. Condensation Particle Counter <ul><li>Particles drawn into instrument </li></ul><ul><li>Particles pass through chamber with alcohol vapor </li></ul><ul><li>Air flows through condensor and vapor condenses on particles </li></ul><ul><li>Particles scatter laser light which is then detected by photo-detector </li></ul>* Information taken from TSI website
  31. 31. Optical Particle Counter <ul><li>Particles drawn through a focused laser </li></ul><ul><li>Resulting scattered light is collected by a mirror and focused on photo-detector </li></ul><ul><li>Concentration derived from count rate and particle size from the pulse heights </li></ul>* Information taken from TSI website
  32. 32. Diffusion Charger (Surface Area) <ul><li>Clean air is ionized </li></ul><ul><li>Ions and aerosol sample streams are mixed and the particles are charged </li></ul><ul><li>Excess ions are removed </li></ul><ul><li>Acts as an inlet conditioner or a size selective sampler </li></ul><ul><li>Ion trap voltage can be changed between TB and A response </li></ul><ul><li>Particles pass through electrometer and are collected on conductive filter </li></ul><ul><li>Amplifies and measures charge on surface of particle </li></ul>* Information taken from TSI website

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